I've never considered derailleur systems to be high maintenance or difficult to work on.
IGHs have their merits, but IMO derailleur systems offer the most bang for the buck. If an individual item should become worn or damaged, it is relatively inexpensive and easy to replace.
As for range of gearing and spacing between gears, I think you'd have to really work at finding a derailleur setup with less of the former and/or more of the latter than an available IGH.
In summary, don't let your immediate perceptions dissuade you from considering a derailleur system. They have been the most cost effective solution for most cyclists for many decades. An attraction of IGHs to the layperson may be that they appear to be simple on the outside, but they are rather more complex on the inside, whereas with derailleur systems, what you see is more or less what you get.
I'm not saying IGH's don't have their place in the grand scheme of things, but I think they offer a false attraction of simplicity, that belies reality, to the layperson.

My remarks may provoke a debate; so be it. I don't deny IGHs their merits, but I don't consider them ascendant over derailleur systems for general use.